The Rock River Arms PPS carbine employs the company's patent-pending Performance Piston System (PPS) to reduce recoil, as well as residue in the upper receiver. It features a purpose-designed bolt carrier, an adjustable gas piston, and an over-the-barrel spring and guide rod arrangement. The result is a departure from the traditional recoil system associated with AR-style firearms. Rock River Arms is expected to offer its PPS carbine to law enforcement later in 2010; the rifle carries a suggested retail price of $1,685.